Antibodies to CD20 have confirmed the hypothesis that monoclonal reagents can be given in vivo to alleviate human diseases. The targeting of CD20 on normal, malignant and auto-immune B-lymphocytes by rituximab has demonstrated substantial benefits for patients with a variety of B-cell lymphomas, as well as some with autoimmune disorders. There has been a notable increase in the survival rates from B-cell lymphoma in the decade since anti-CD20 therapy was introduced.
Monoclonal antibody (mAb) therapy with the anti-CD20 mAb rituximab represents one of the most important advances in the treatment of lymphoproliferative disorders in the last 30 years. Prior to its introduction, there had been only modest improvement in the treatment outcome of diseases such as follicular (FL) and diffuse large B-cell lymphoma (DLBCL). However, the use of rituximab, particularly in combination with various chemotherapy/radiotherapy regimes, has significantly improved all aspects of the survival statistics for these patients. In addition, rituximab is approved, or being investigated for the treatment of many other hematologic disorders ranging from other malignancies, such as chronic lymphocytic leukemia (CLL), to autoimmune disorders, such as immune and thrombotic thrombocytopenic purpura and rheumatoid arthritis (Lim et al. Haematologica. 2010; 95(1): 135-143).
Despite the success of anti-CD20 therapy, resistance occurs in about half of the patients, resulting in non-response to treatment or early relapse of the original disease.
Number of cells expressing CD20 in addition to CD20 cell surface density has been clearly shown to determine anti-CD20 mAb sensitivity at an early stage (Tsai et al., 2012). Therefore investigating the regulation of CD20 expression is a prime interest.
Molecular discrimination of responders versus non responders to anti-CD20 antibody becomes a major clinical interest, and there is a permanent need in the art for prognostic biomarkers that could assist physicians in providing patients optimized care management with anti-CD20 antibody.